Bench support base



FIG. 1 is a front isometric view of a bench support base showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a back elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a further isometric view of my new design.

The broken lines are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a bench support base, as shown and described. 